1. Field of the Invention
The present invention relates generally to drawing programs, and in particular, to a method, apparatus, and article of manufacture for navigating in space within a drawing program.
2. Description of the Related Art
Computer-implemented graphics systems have been widely used by designers, illustrators, drafters, and engineers for a number of years. Most such graphics systems use a two-dimensional (2D) graphical user interface (GUI) to display graphical images, such as 2D or three-dimensional (3D) models, schematic diagrams, photorealistic images, etc. When a 3D space is displayed in a 2D GUI, the operator is responsible for perceiving the third dimension, and may be aided by perspective views, rendering, shadows or other visual cues provided by the graphics systems. However, such visual cues are limited and may not assist the user as desired.
The graphical images being displayed in graphics systems may comprise one or more geometric entities such as pipes, plumbing, electrical wiring, columns, chairs, tables, signs, etc. in the three-dimensional space. When placing such a geometric entity, the prior art fails to provide visual feedback as to where the geometric entity lies in three-dimensional space. This may be particularly problematic when placing or linking together multiple geometric entities in three dimensional space since the operator cannot clearly identify the three-dimensional plane(s) where the geometric entity is being placed. For example, when placing ducting for an HVAC (heating ventilation air conditioning) system, the operator may desire to place the ducting on multiple different planes in order to provide proper ventilation around existing structures (e.g., walls, beams, studs, etc.). Without visual feedback, it is very difficult, if not impossible, to identify and select the directions and planes where the ducting is being placed.
Consequently, there is a need in the art for improved techniques for providing visual clues to assist in the placement of geometric entities in 3D space in graphics systems.